What is a functional dependency with example?

In functional dependency we can obtain the value of another attribute from given attribute. For example, If we know the value of student roll number, we can obtain student address, marks etc. By this, we say that student address and marks is functionally dependent on student roll number.

What is meant by functional dependency in database?

A functional dependency is a constraint that specifies the relationship between two sets of attributes where one set can accurately determine the value of other sets. The attribute set on the left side of the arrow, X is called Determinant, while on the right side, Y is called the Dependent.

What is meant by functional dependency in normalization?

Functional dependency (FD) is a set of constraints between two attributes in a relation. Functional dependency is represented by an arrow sign (→) that is, X→Y, where X functionally determines Y.

What is functional dependency give some examples demonstrate trivial and non trivial functional dependencies with examples?

If a functional dependency X->Y holds true where Y is not a subset of X then this dependency is called non trivial Functional dependency. For example: An employee table with three attributes: emp_id, emp_name, emp_address. Refer: trivial functional dependency.

What is partial functional dependency?

Partial Functional Dependency : A functional dependency X->Y is a partial dependency if Y is functionally dependent on X and Y cannot be determined by any proper subset of X. For example , we have a relationship AC->B , A->D and D->B.

What do you understand by functional dependency and transitive dependency in DBMS?

Transitive dependency is expressing the dependency of A on C when A depends on B and B depends on C. A functional dependency is an association between two attributes of the same relational database table. One of the attributes is called the determinant and the other attribute is called the determined.

What is trivial dependency explain with an example?

The Trivial dependency is a set of attributes which are called a trivial if the set of attributes are included in that attribute. So, X -> Y is a trivial functional dependency if Y is a subset of X. For example: Emp_id.

What is functional dependency explain its type?

Functional Dependency (FD) is a constraint that determines the relation of one attribute to another attribute in a Database Management System (DBMS). Functional Dependency helps to maintain the quality of data in the database.

What do you mean by functional dependency in DBMS?

– Functional Dependency is when one attribute determines another attribute in a DBMS system. – Axiom, Decomposition, Dependent, Determinant, Union are key terms for functional dependency. – Four types of functional dependency are 1) Multivalued 2) Trivial 3) Non-trivial 4) Transitive.

What does trivial functional dependency mean?

Trivial Functional Dependency. In Trivial Functional Dependency,a dependent is always a subset of the determinant.

Non-trivial Functional Dependency. In Non-trivial functional dependency,the dependent is strictly not a subset of the determinant.

Multivalued Functional Dependency.

Transitive Functional Dependency.

What is minimal set of functional dependencies?

A minimal cover of a set of functional dependencies (FD) E is a minimal set of dependencies F that is equivalent to E. The formal definition is: A set of FD F to be minimal if it satisfies the following conditions − Every dependency in F has a single attribute for its right-hand side.

What is FAFSA dependency?

FAFSA Dependency. Though many families believe parents are no longer financially responsible for a child once they graduate from high school, tax and financial aid guidelines differ pertaining to dependency. The majority of student aid programs are based on both student and parent bearing the responsibility for payment of the costs of a student’s college education.